Dexmedetomidine is associated with intraoperative hypotension and may bring poor postoperative outcomes

I read with interest the article by Xin et al. in which they reported that dexmedetomidine alleviated postoperative delirium (POD) in elderly patients with mild cognitive impairment. Dexmedetomidine is a central α‐2 adrenergic agonist and has anti‐inflammatory properties, but its effects on POD are still controversial. Moreover, bradycardia and hypotension are two of side effects of dexmedetomidine. In Xin's study, patients randomized to dexmedetomidine were not more likely to have clinically important hypotension which was defined as systolic blood pressure (SBH) less than 95 mmHg. However, compared with SBH, mean artery pressure (MAP) is more reliable and closely related to organ perfusion. Edokpolo et al. reported that the patients receiving a low dose of dexmedetomidine (0.3 μg/kg) with propofol had a larger decrease in MAP, from their preprocedural baseline to the lowest value observed during the procedure, compared with the patients receiving propofol alone. In patients having cardiac surgery, perioperative dexmedetomidine infusion was demonstrated to even worsen delirium and kidney injury by provoking hypotension. Intraoperative hypotension has been concluded as a hazard to patient and associated with postoperative adverse events. Results from a systematic review suggested that end‐organ injury occurs when MAP is less than 80 mmHg for prolonged period (>10 min) and less than 70 mmHg for shorter duration. Furthermore, one more recent study found that even 1‐min hypotension (MAP < 65 mmHg) may lead to increased postoperative 30‐day mortality, acute myocardial infarction or acute ischemia stroke. Dexmedetomidine has been used widely in anesthesia because of many benefits, but its association with adverse clinical outcomes should not be ignored. In clinical work, we should balance the advantages and disadvantages, and use dexmedetomidine cautiously in elderly patients with attention to preventing hypotension.